I'm using PJ Naughter's (www.naughter.com) CSerialPort v1.11 class for serial port communication on the Windows operating system. I'm wondering if this class or something else (like WIN32 API or MFC) comes with a function that lets me terminate all writes in progress and clear the write buffer. My problem is that I'm doing a write in a loop and the write is started the second time before it finishes the first time. This makes my application preform poorly, and causes many fatal errors. I looked through the documentation and found a few functions that looked like they might do the job but they didn't work (i might have used them wrong). Can someone point me in the right direction?